Fused silica is produced by melting high-purity silica sand. The melting is typically accomplished by heating the silica sand in an electric furnace, which produces a large ingot of fused silica. During the fusion process, a hard shell forms on the outer layer of the ingot where the heat has not amorphized the crystalline silica sand.
In order to provide the fused silica in a form for commercial applications, the large ingot is removed from the furnace and cooled to ambient temperature over a period of days. After the ingot is cooled, the ingot is crushed into particulate form using large industrial crushers.
There are several problems with this batch process including requiring large amounts of electricity to melt the silica sand, significant time to cool the produced ingot, difficulty moving the large ingot through the various stages, and hazardous working conditions during the intense crushing steps.
What is needed therefore is a process for producing fused silica that will be more economical and environmentally friendly.